Replication data for empirical illustration in Section 6 of "Conical FDH
Estimators for Testing Returns to Scale and Making Inference about Changes
 in Productivity" by Alois Kneip, Leopold Simar and Paul W. Wilson,
Econometric Reviews, forthcoming (2025).

Files 'cities-3.data' contains nine columns with the
following variables that are described in Section 6 of the paper:
     1 --- id;
     2 --- year;
     3 --- region;
     4 --- state FIPS code;
     5 --- census division;
     6 --- x1 (adjusted with CPI);
     7 --- y1 (population);
     8 --- y4 (land area); and
     9 --- reduced-dimensional output (with y2 adjusted by CPI),
           omitting y1 (population) and y4 (land area); i.e., reduction
           of y2, y3, y5 and y6.
There are 2,924 lines in the file, corresponding to 2,924 observations.
See the discussion in Section 6 of the paper for more details.
